Brotli replaces Zopfli, Google’s current web compression engine responsible for reducing the size of design assets including styles and fonts delivered from websites to the browser. According to engineer Ilya Grigorik, Brotli, named after a type of German bread, is now ready to roll out and should make it into the next release version of Chrome.
The algorithm has been built as a complete data format to offer 20-26 percent greater data compression than is possible with Zopfli. Zopfli was launched in 2013 and quickly became a popular solution for developers looking to compress their content. This allows the browser to download it more quickly and display the complete page to the user sooner than if no compression was used.
Google cites advantages including faster page loads, reduced power consumption and less data usage. In a September 2015 blog post introducing the technology, Compression Software Engineer Zoltan Szabadka wrote: “The smaller compressed size allows for better space utilization and faster page loads. We hope that this format will be supported by major browsers in the near future, as the smaller compressed size would give additional benefits to mobile users, such as lower data transfer fees and reduced battery use.”
Because Brotli is a new data format, it needs to be adopted and supported by rival browsers such as Mozilla Firefox and Microsoft Edge if it is to be successful. Mozilla has already pledged support and intends to ship Firefox 44 with Brotli compatibility in the next few weeks but other vendors have yet to reveal their plans for Brotli support.
There are very few requirements for developers using Brotli to make their websites load faster. The most important one is that the format mandates the use of the secure HTTPS connection type as Google continues to push the web away from the older and unprotected HTTP. Sites using Brotli will load more quickly than those without while giving users the security of an encrypted connection.
When Google first announced Brotli, it managed to ignite allegations of sexism for its decision to suffix Brotli files with the “.bro” file extension, a term that many thought favoured male programmers due to the colloquial term “bro” frequently used to refer to males in the U.S. Google later said “there will be no ‘.bro’ in Brotli” despite never having publicly revealed the file extension.
Brotli is now in the “intent to ship” stage of the Chrome development cycle so should make it into the next public release unless a major bug is found before then. It may take time before websites start using the new algorithm but the popularity of its predecessor and the new features it includes makes it more likely Brotli will find an audience.
